The Pragmatic Impact of Frailty on Outcomes of Coronary Artery Bypass Grafting.

Abstract

Although not formalized into current risk assessment models, frailty has been associated with negative postoperative outcomes in many specialties. Using administrative coding, we evaluated the impact of frailty on in-hospital death, complications, and resource use in a nationally representative cohort of patients undergoing isolated coronary artery bypass grafting (CABG). Patients aged 18 years and older who underwent isolated CABG across the United States were identified using the 2005 to 2016 National Inpatient Sample. Frailty was defined using a derivative of the validated Johns Hopkins Adjusted Clinical Groups frailty-defining diagnosis indicator. Mortality, length of stay, inflation-adjusted costs, and postoperative complications were evaluated using multilevel multivariable regression. Of an estimated 2,137,618 patients undergoing isolated CABG, 85,879 (4.0%) were considered frail. The proportion of frail patients increased over the study period (nonparametric test for trend P = .002), while annual mortality rates declined (nonparametric test for trend P <.001). Frail patients were older (68.9 ± 10.7 years vs 65.0 ± 10.6 years, P < .001), and more commonly female (32.8% vs 26.2%, P < .001). After adjustment, frailty was associated with increased odds of in-hospital death (adjusted odds ratio [AOR], 2.49; 95% confidence interval [CI], 2.30-2.70; P < .001), major complications (AOR, 2.55; 95% CI, 2.39-2.71; P < .001), increased length of stay (AOR, 1.40; 95% CI, 1.09-2.11; P < .001), and costs (AOR, 1.03; 95% CI, 1.02-1.07; P < .001). Frailty, as identified by administrative coding, serves as a strong independent predictor of death and complications after CABG. Incorporation of frailty into risk models may aid in counseling patients about operative risk and benchmarking outcomes.